1. Technical Field
The present application present application relates to field of external doors and windows of buildings, and in particular, relates to an energy-saving security composite window.
2. Background Art
At present, aluminum alloy windows and plastic-steel windows are widely used in China. Aluminum alloy profiles that are mainly used by the aluminum alloy windows are hollow aluminum alloy profiles with wall thickness equal to or greater than 1.4 mm. Key fabrication procedures of doors and windows are corner combination and assembly. According to a main process of the corner combination, connections between corners of door and window frames and sashes, and connections between a side frame and a muntin are mostly achieved by riveting, corner brace combination, or screw connection. The connection manner is used for connecting a hollow metal with another hollow metal, which cannot effectively ensure overall performances of doors and windows such as sealing, strength, heat insulation, and sound insulation nor effectively prevent heat conduction between indoors and outdoors to reduce running time of household temperature-controlled appliances, eventually resulting in severe energy waste. Usually, three-cavity or multi-cavity PVC plastic profiles with a wall thickness equal to or greater than 2.2 mm are used for the plastic-steel windows, where one cavity is provided with a reinforced steel liner with a wall thickness being 1.5 mm. The corners of door and window frames, a side frame and a muntin are welded together by hot melting plastic profiles, which achieves only connection of the plastic profiles rather than perform any connection for the reinforced steel liners in the cavity. With this process, the overall strength of the doors and windows is greatly reduced, and the doors and windows are easy to deform, thereby leading to poor anti-wind pressure performance, poor anti-warping performance, poor anti-destruction performance, and shorter service life.